1. Field of the Invention
The invention concerns a working pressure control mechanism for lapping, honing, and grinding machines.
2. Description of the Prior Art
In machining with these types of machines, the pressure exerted by the tool (the lapping, honing, or grinding wheel) on the surface of the workpiece is of critical importance. With excessive pressure, there is the danger of adverse effects on the desired quality of the surface, possibly cold welding of workpiece and tool, and in the case of lapping machines, the pulling away of the lapping film containing the lapping compound. With insufficient pressure, machining times become unnecessarily long and machining costs increase.
In the past, as a rule, the pressure on the workpiece in such machines has been adjusted by hand, by hydraulic or pneumatic thrust, by adjusting the pressure, i.e., force of the machining wheel in the axial direction against the medium which moves the workpiece. German published application No. 22 04 581 discloses a working pressure control mechanism for a lapping or honing machine, with which the spinnable machine shaft bearing the tool is rotatably mounted in an axially translatable piece such that said shaft is carried along by said piece in the direction of the advance, with the working pressure being adjusted according to a calculated or empirically determined curve, wherewith, e.g., a suitable jig is used as the programming control organ. Such controls can only follow fixed values, which often differ substantially from actual conditions in practice.